package com.hou.houlymall.cart.interceptor;

import com.hou.common.constant.AuthServerConstant;
import com.hou.common.constant.CartConstant;
import com.hou.common.vo.MemberRespVo;
import com.hou.houlymall.cart.vo.UserInfoTo;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.util.UUID;

/**
 * @author H
 * @create 2021-08-16 18:25
 * @description 在执行目标方法之前，判断用户的登录状态。并封装传递给controller目标请求
 *
 */
public class CartInterceptor implements HandlerInterceptor {

    public static ThreadLocal<UserInfoTo> threadLocal = new ThreadLocal<>();

    /**
     * 目标方法执行之前
     * 此时只往 userInfo 里面封装东西，存到 threadLocal 里面
     * @param request ...
     * @param response ...
     * @param handler ...
     * @return ...
     * @throws Exception ...
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        UserInfoTo userInfoTo = new UserInfoTo();
        HttpSession session = request.getSession();
        MemberRespVo member = (MemberRespVo) session.getAttribute(AuthServerConstant.LOGIN_USER);
        if (member != null){
            //用户已登录 -> 封装用户信息
            userInfoTo.setUserId(member.getId());
        }

        Cookie[] cookies = request.getCookies();
        if (cookies!=null && cookies.length>0){
            //浏览器中已有 cookies -> 是否有临时用户
            for (Cookie cookie : cookies) {
                //user-key
                String name = cookie.getName();
                //如果有 user-key 证明有临时用户，封装起来
                if (CartConstant.TEMP_USER_COOKIE_NAME.equals(name)){
                    userInfoTo.setUserKey(cookie.getValue());
                    userInfoTo.setTempUser(true);
                }
            }
        }

        //如果没有临时用户一定分配一个临时用户
        if (StringUtils.isEmpty(userInfoTo.getUserKey())){
            String uuid = UUID.randomUUID().toString();
            userInfoTo.setUserKey(uuid);
        }
        //目标方法执行之前
        threadLocal.set(userInfoTo);

        return true;
    }


    /**
     * 业务执行之后；分配临时用户，让浏览器保存
     * 此时 userInfo 已经封装好，从 threadLocal 里取出来，存到cookie里面，下次用
     * @param request ...
     * @param response ...
     * @param handler ...
     * @param modelAndView ...
     * @throws Exception ...
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        UserInfoTo userInfoTo = threadLocal.get();

        //如果没有临时用户一定保存一个临时用户
        if (!userInfoTo.isTempUser()){

            Cookie cookie = new Cookie(CartConstant.TEMP_USER_COOKIE_NAME, userInfoTo.getUserKey());
            cookie.setDomain("houlymall.com");
            cookie.setMaxAge(CartConstant.TEMP_USER_COOKIE_TIMEOUT);
            response.addCookie(cookie);
        }
    }
}
